This international meeting on hereditary breast and ovarian cancer follows on the heels of prior individual symposia previously organized separately in Europe and in United States. The meeting structure consists of an introductory session on the general topic of prevention and early diagnosis of breast and ovarian cancer, five additional plenary sessions dealing with various aspects related to the biology of these tumors and to the clinical implications, and ending with a session including a round table that will deal with strategies in management of this problem. Although the focus of the five plenary sessions is on hereditary cancers (making up the minority of women afflicted with these cancers), it has become increasingly obvious that the lessons learned from their occurrence within families are also applicable to a variable extent to those that occur 'sporadically'-that is, without prior knowledge of a hereditary condition. In fact, the progress in prevention, diagnosis and treatment of these cancers has gone hand in hand with what is being learned in hereditary cancer: predisposition to cancer in relation to the host's hormonal environment, magnetic resonance imaging in early detection, implications of DNA- repair defects resulting from specific genetic abnormalities in causing cancer. We anticipate that this meeting, bringing together experts from two continents, and attended by interest young workers in the field will lead to discussion on a number of issues relating to disease-risks, and the challenges on how to address these risks at earlier (and more favorable) circumstances. Public Health Relevance: Cancers of the breast and ovary account for approximately 60,000 deaths annually in the United States. Hereditary cancers, although only accounting for 10% of these occurrences, lead the way in the determination of relevant genetic characteristics and in the implementation of preventive and surveillance measures. Thus this meeting will be of interest to workers dealing with all aspects of breast and ovarian cancers.